
ai + security + alpha CEO @theori_io / @xint_official → building the world's best AI hacker 9x DEF CON CTF winner CMU CS '11 | founded PPP & MMM
Seoul / SF
Joined April 2010
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It's strange how often this happens. We spend real time finding novel attack surface in a target and building a working exploit, and within hours of finding it, multiple other people claim bugs with similar capability in the same target.
Coincidence, or is something fishy going on? This isn't the first or second time for us.
Not sure they're all dupes, but of the ones we've seen so far, it's about half and half. Meanwhile, we hold ours until we've fully analyzed the impact. We like to hand-pick findings and polish the write-ups before sending them to maintainers and vendors, so we add as little to their burden as possible. But that costs us time, especially with whatever phenomenon this is.
Maybe we should just report as soon as we find something plausible. Then again, I'm not sure that's even what's going on.
It's possible that everyone became super hackers now, which isn't the worst thing, I guess. We've always wanted more competent people and teams to help with finding vulns :p (but it still hurts when you get sniped)
At least after all these live-fire drills we are going through, hopefully we’ll be in better shape to deploy patches when even nastier bugs land in the future.
We have an epic bug to show off soon, but after seeing the marketing and branding of the PHP bugs (it's well done and I enjoyed much), I'm not convinced we can beat that level of branding despite our bug being "holy grail of web server pwn" 😭
We could've used this "feature" to lower Xint's cost significantly. Obviously we decided to responsibly disclose the bug. It was promptly fixed by @OpenAI team, but $600 for something that has far greater business / financial impact was a little insulting tbh 😭
🫸👻🫷🧵
Let's talk GhostCompact:
What if you could cut your output token costs on OpenAI by 97-99%? 🤑
Our researcher @tjbecker found a discrepancy between the actual token costs burned versus what ended up being billed. He had a hunch and used Xint to validate that there was a logic bug in OpenAI's compaction feature released in February 2026 that led to billing based on compacted output and not on the actual tokens consumed.
xint.io/blog/openai-compacti…
This legit makes me want to go back to school after 15 years since I graduated. If you are a CMU student, make sure you take this opportunity! You’ll probably learn far more than just compilers from @realGeorgeHotz.
syllabus: gist.github.com/geohot/47685…
Brian Pak retweeted
#Pwn2Own Ireland schedule is finalized.
Team Xint attempts (Ireland time):
LiteLLM - Tuesday 9:30
Philipps Hue - Tuesday 18:30
Home Assistant - Wednesday 9:30
Oracle AI Database - Wednesday 11:45
Pixel 10 - Thursday 11:15
zerodayinitiative.com/blog/2…
Hey everyone. We’ve seen the discussions around Copy Fail (CVE-2026-31431) and the disclosure process. We appreciate the passion from distro maintainers, defenders, and the broader Linux community. This is a serious issue, and we want to share some context on our side in good faith. 🧵
Some have also raised concerns about us releasing the exploit publicly. We have experience writing N-day exploits and know that monitoring git commits for fixes is common practice in offensive security. Attackers were likely already aware and exploiting this within the a few days after the kernel fix landed. With AI coding tools today, turning a CVE plus commit into a working exploit happens in hours anyway.
We’re grateful to the kernel security team and everyone working hard on patches. Looking ahead, we’re sure Xint and our researchers will uncover many more critical vulnerabilities. We’ll try our best next time to create less chaos for folks. Happy to discuss improvements openly.
Thanks for reading. Let’s keep making Linux stronger together. 🙏


